Many modern vehicles include radar scanning systems to assist the vehicle in such applications as automated emergency breaking (AEB) to stop the vehicle when objects are detected in a given vehicle's path. Traditional non-scanning radar receivers observe the entire system field of regard (e.g., area where objects are to be detected) and collect backscatter (e.g., reflections of transmitted energy) from objects in the field of regard. Typical scanning receiver operation is to scan successive adjacent regions at a fixed scan rate, starting on one edge of the instantaneous field of view, moving the beam such that the edge of the beam slightly overlaps the previous field of view, and so on until the entire system field of regard has been scanned.
In a scan time example for a typical receiver, assuming a frame rate of 20 frames per second (FPS), each field of regard should be sequentially scanned within 50 msec. With azimuth only scan, with field of regard of 60 degrees, and field of view at 6 deg, the dwell time is about 5 msec at each beam position in the field of regard. The minimum dwell time at each beam position is governed by system accuracy requirements. Wider fields of regard reduce the dwell time at each position. As dwell time decreases, the amount of data collected at each field of view position within the field of regard decreases, which can decrease the accuracy of a detection system.